WorldCat Identities

Di Renzo, Francesco (Chimiste)

Overview
Works: 13 works in 14 publications in 2 languages and 14 library holdings
Roles: Other, Thesis advisor, Opponent
Publication Timeline
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Most widely held works by Francesco Di Renzo
Zeolite nanocrystals for biomedical applications by Kamila Goldyn( )

2 editions published in 2018 in English and held by 2 WorldCat member libraries worldwide

The properties of nanozeolites, namely, large surface area, hydrothermal stability and non-toxic nature, enable their utilization in forward-looking applications, including biomedicine (sensors, drug and gas delivery) and microbiology (antibacterial agents). Hence, a lot of research has been devoted to study the new biomedical applications using zeolitic materials, their full potential has still not been fully unveiled.It is well recognised that growing resistance to already established treatments of tumors and bacterial infections using radiotherapy and antibiotics is a distressing matter. Therefore, the development of new therapeutic strategies towards above issues is of great demand.The goal of this PhD research is to synthesise and post-synthetically modify nanosized zeolites for biomedical applications. This involves the ion-exchange of zeolite with various cations to find the most suitable one for desired applications in regards to antimicrobial treatment, tumour tissue reoxygenation and gas delivery.In this study, we report: (i) the effect of copper modified nanosized FAU type zeolite on ESKAPE type bacteria (Chapter 3), (ii) the metal containing nanozeolite as a tool for tissue oxygenation and visualisation using MRI (Chapter 4), and lastly (iii) the use of FAU nanozeolite as nitric oxide and carbon dioxide gas vector to prevent life threatening conditions (Chapter 5)
Production photocatalytique de produits chimiques et d'hydrogène à partir de biomasse by Valeriia Maslova( )

1 edition published in 2020 in English and held by 1 WorldCat member library worldwide

Sustainable industrial conversion of biomass as renewable and abundant feedstock is becoming increasingly attractive as to synthesize high-value-added products, which can be utilized in energy sector, food, polymer, cosmetics and pharmacological industries, as well as in production of fine chemicals. In this work, with the aim to tackle several approaches towards sustainable chemistry, we used biomass derived 5-hydroxymethyl-2-furfural (HMF) in aerobic photo-oxidation. Partial oxidation products of this reaction, for instance 2,5-diformylfurane (DFF) and 2,5-furane dicarboxylic acid (FDCA), are of particular interest for the polymer industry. Glycerol as a multi-ton by-product of biodiesel production was also subjected to anaerobic photo-reforming in order to obtain hydrogen gas and liquid-phase products. Solar-assisted reactions were performed by means of heterogeneous photocatalysis, in mild conditions such as atmospheric pressure, room temperature and water as a benign solvent. Titanium dioxide was used as a photo-active catalyst. Despite of the fact that TiO2 is the most active, non-toxic and low-cost material, its wide bandgap allows employing only UV irradiation that covers just 5% of the solar spectrum. Thus, the introduction of noble metal nanoparticles makes it possible to embrace the problem of visible light absorption as well as to reduce electron-hole pair recombination in the semiconductor. Titanium dioxide was synthesized in the form of nano-powder using a microemulsion-mediated system. Au, Ag, Pt noble metal nanoparticles, Au-Ag, Au-Cu alloys and core-shell nanoparticles, and NiO metal oxide nanoparticles were deposited on TiO2 support. This was done ether by deposition-precipitation or incipient wetness impregnation method. Metal precursor salts or pre-formed nanoparticles were employed in the latter method. The prepared catalysts were characterized by XRD, DRS, N2 physisorption, TEM, SEM and RAMAN analysis. Their catalytic activity was compared to that of commercially available titanium dioxide powders such as P25 and DT-51. The influence of the support, the size and type of the deposited metal and metal oxide nanoparticles on the photo-catalytic transformation of HMF and glycerol was evaluated. In the case of HMF, the influence of the base addition and the oxygen content on the reaction selectivity was also studied. The effect of the crystalline phase composition and morphology of TiO2 in the glycerol photo-reforming reaction was assessed as well. The surface of the synthesized TiO2 nano-powders was investigated by means of Surface Organometallic Chemistry (SOMC) approach. In particular, the surface was characterized by chemical titration and DRIFT techniques. Furthermore, the SOMC concept allowed preparing of well-dispersed Pt nanoparticles on the TiO2 surface. The photo-catalytic activity of this sample in the glycerol photo-reforming process was tested and compared to that of other Pt-containing catalysts prepared by conventional technics. In view of avoiding the agglomeration and sedimentation of suspended titania powders in water media, thick films of synthesized and commercial TiO2 were deposited on a conductive substrate using screen-printing technique. The prepared electrodes were characterized by profilometry, SEM, XRD, optical, electrical and photo-electrochemical methods
De la nanoémulsion aux MTS (Matériaux aux Tensioactifs Structurants) by Delphine Desplantier-Giscard( Book )

in French and held by 1 WorldCat member library worldwide

L'OBJECTIF PRINCIPAL DE CETTE THESE EST L'ETUDE DE LA FORMATION DE MATERIAUX MESOPOREUX AUX TENSIOACTIFS STRUCTURANTS (MTS) SILICIQUES OU ALUMINOSILICIQUES A TAILLE DE PORES CONTROLEE, SYNTHETISES A PARTIR DE NANOEMULSIONS COMPOSEES DE TENSIOACTIFS CATIONIQUES (ALKYLTRIMETHYLAMMONIUM) ET D'AGENTS GONFLANTS. LA CARACTERISATION DU SYSTEME TERNAIRE (SANS SILICE) A MIS EN EVIDENCE L'INSTABILITE DE LA NANOEMULSION QUI DEMIXE. LORS DE LA SYNTHESE DES MATERIAUX HYBRIDES, NOUS AVONS CONSTATE L'EFFET STABILISANT DES SILICATES. LA SOLUBILISATION D'AGENT GONFLANT DE NATURE CHIMIQUE DIFFERENTE (AROMATIQUE OU ALIPHATIQUE) A MONTRE DES MECANISMES DE SOLUBILISATION DISTINCTS ET L'INEFFICACITE DES ALCANES POUR LA SYNTHESE DES MTS A GRANDS PORES. L'ETUDE DES PARAMETRES DE SYNTHESES QUI INFLUENCENT LES PROPRIETES DU SOLIDE (SOURCE DE SILICE, RAPPORT OH /SIO 2, RAPPORT SI/AL), NOUS A PERMIS DE MAITRISER ET D'OPTIMISER LA SYNTHESE DES MTS A GRANDS PORES PAR STABILISATION DE LA NANOEMULSION. LES CINETIQUES DE FORMATION DE CES SOLIDES ONT MONTRE DES MECANISMES DIFFERENTS POUR LA SYNTHESE DE MTS ALUMINOSILICIQUES ET SILICIQUES. DES MTS PRESENTANTS DES DIAMETRES DE PORES SUPERIEURS A 80 A, UNE ETROITE DISPERSION DE LA TAILLE DES PORES, UN VOLUME POREUX ELEVE (2 ML/G ENVIRON) ET UNE SURFACE SPECIFIQUE IMPORTANTE (1000 M 2/G ENVIRON) ONT ETE SYNTHETISES. NOUS AVONS MIS EN EVIDENCE LE CARACTERE HYDROPHOBE DES MTS NON CALCINES POREUX SYNTHETISES A PARTIR D'UNE NANOEMULSION. CES MATERIAUX OUVRENT DES PERSPECTIVES INTERESSANTES DANS LE DOMAINE DES ADSORBANTS. UNE ETUDE COMPLEMENTAIRE SUR LA RESISTANCE MECANIQUE, LORS DE LA MISE EN FORME DES MTS POUR LES UTILISER EN TANT QUE CATALYSEUR, A ETE REALISEE. UNE PERTE DE STRUCTURE A ETE OBSERVEE POUR UNE PRESSION DE COMPACTAGE SUPERIEURE A 0,8 KBAR. MAIS POUR UNE TELLE PRESSION LA POROSITE DES MTS DE 40 A EST CONSERVEE, IL EN RESULTE UNE AUGMENTATION DE L'ACTIVITE CATALYTIQUE OBSERVEE LORS D'UN TEST CATALYTIQUE D'HYDROCONVERSION DU N-HEXADECANE (NC 1 6)
Dépolymérisation catalytique de la cellulose couplée à des techniques d'activation non thermiques by Maud Benoit( )

1 edition published in 2012 in French and held by 1 WorldCat member library worldwide

Avec la disparition progressive des réserves de carbone fossile, un intérêt tout particulier est aujourd'hui porté sur la valorisation de la biomasse notamment la cellulose. Elle représente une source importante (1,3 Millions de tonnes) et peu onéreuse (< 10 €/kg) de carbone renouvelable. L'utilisation de la cellulose en tant que matière première pour la chimie fine apparait comme une solution attractive tant sur le plan économique qu'environnemental. Néanmoins, la présence de liaisons hydrogène intra et extra réseau lui confère une stabilité élevée (forte cristallinité) la rendant insoluble dans les solvants organiques usuels et dans l'eau. Ainsi, l'hydrolyse de ce polymère en glucose ou oligosaccharides, en présence d'un catalyseur solide est limitée par les interactions catalyseur/cellulose. C'est pourquoi, des prétraitements de la cellulose sont souvent utilisés permettant alors d'augmenter les interactions avec les catalyseurs solides. Toutefois, les méthodes développées dans la littérature sont coûteuses ou néfastes pour l'environnement. L'objectif de cette étude est le développement d'activations physiques de la cellulose, respectueuses de l'environnement, permettant l'hydrolyse de ce polymère en présence d'un catalyseur solide. L'activation de la cellulose est effectuée par ultrasons ou par plasma atmosphérique non thermique. Ces méthodes d'activation permettent d'augmenter considérablement le rendement en glucose en modifiant i) la taille des particules et/ou ii) le degré de polymérisation et/ou iii) la cristallinité de la cellulose. Enfin, à partir des sucres issus de la dépolymérisation de la cellulose, le 5- hydroxyméthylfurfural (molécule plateforme) peut être obtenu. Cette synthèse sera étudiée et plus particulièrement la nature du solvant, qui impacte la sélectivité de cette réaction. Lors de ces travaux, un intérêt tout particulier est porté sur l'utilisation de glycérol et de carbonate de glycérol en tant que solvant
Production of Solar Fuels using CO2 by Bhanu Chandra Marepally( )

1 edition published in 2017 in English and held by 1 WorldCat member library worldwide

In view of the recent alarming rate of depletion of fossil fuel reserves and the drastic rise in the CO2 levels in the atmosphere leading to global warming and severe climate changes, tapping into all kinds of renewable energy sources has been among the top priorities in the research fields across the globe. One of the many such pathways is CO2 reduction to fuels using renewable energies, more commonly referred as photo-electro-catalytic (PEC) cells. Experimental tests were carried out on various types of catalysts in both the gas and liquid phase cells (lab-designed) to understand the different selectivity, productivity and the reaction products obtained. For the studies on the EC reduction of CO2 in gas phase cell, a series of electrodes (based on Cu, Fe, Pt and Cu/Fe metal nanoparticles - NPs - deposited on carbon nanotubes - CNTs - or carbon black and then placed at the interface between a Nafion membrane and a gas-diffusion-layer) were prepared. Under gas phase, the formation of ≥C1 products (such as ethanol, acetone and isopropanol) were observed, the highest being for Fe and closely followed by Pt, evidencing that also non-noble metals can be used as efficient catalysts under these conditions. To enhance the net fuels, a different set of electrodes were also prepared based on substituted Zeolitic Imidazolate (SIM-1) type MOF coatings (MOF-based Fe-CNTs, Pt-CNTs and Cu/Fe-CNTs) and Pt-MOF showed improved fuels. Moving to the studies on the EC reduction of CO2 in liquid phase cell, a similar set of electrodes were prepared (metal NPs of Cu, Fe, Pt, Ru and Co deposited on CNTs or carbon black). For liquid phase conditions, in terms of net C-products, catalytic electrodes based on Pt topped the class, closely followed by Ru and Cu, while Fe got the lowest position. The probable underlying reaction mechanism was also provided. In order to improve further the performances, varied sized metal NPs (Ru, Fe, Pt and Cu) have been synthesized using different techniques: (i) impregnation (ImR) route to achieve NPs in the size range of 10-50 nm; (ii) organometallic (OM) approach to synthesize uniform and ultrafine NPs in the size range of 1-5 nm (i.e., Fe NPs were synthesized through a novel synthesis route to attain 1-3 nm NPs); (iii) Nanowire (NW) top-down approach to obtain ultrafine copper metal NPs in the size range of 2-3.8 nm. The enhancements in the fuel productivity were found to be 5-30 times higher for the smaller metal NPs over the larger metal NPs and moreover, with reduced metal loading from 10 to 1-2 wt %. A different set of electrodes based on nano-foams (Cu NF and Fe NF on Cu foil, Fe foil, Al foil, Inconel foil and Al grid/mesh) prepared via electro-deposition were also investigated, to further improve CO2 to fuels conversion. After, optimization of deposition and voltage using cyclic voltammetry, the fuels improved by 2-10 times over the highest net fuels achieved using metal NPs doped CNT electrodes
Chimie organométallique de surface sur l'oxyde de titane by Tapish Saboo( )

1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

Surface organometallic chemistry (SOMC) is used to design well-defined catalysts. It has been employed here to lay the foundation of SOMC on photocatalytic support, a previously little if any explored area. TiO2 anatase was used as the photocatalytic support due to its high stability, photoactivity and nontoxicity. The chemical nature and the surface density of the reactive moieties found on anatase support has been determined. A Ta complex, well-known in literature, was used to conduct the first principal studies regarding the interaction between the surface and the organometallic complex. The results provide solid insights into organometallic grafting and metal to metal charge transfer mechanisms for developing well-defined photocatalysts by SOMC
Hybrid mesoporous materials for the oxidative depolymerization of lignin into valuable molecules by Andreia Nunes( )

1 edition published in 2016 in English and held by 1 WorldCat member library worldwide

La lignine est un des polymères naturels les plus abondants et le seul constituant de la biomasse basé sur des unités aromatiques et, à ce titre, représente une ressource renouvelable prometteuse pour la production durable de molécules organiques plus complexes. Les travaux de cette thèse portent sur le développement de matériaux catalytiques capables de transformer sélectivement la lignine en molécules fonctionnelles de base, hautement oxygénées, et l'étude de leur mise en oeuvre en condition alcaline oxydante en utilisant le peroxyde d'hydrogène comme donneur d'oxygène. Différentes familles de matériaux hybrides de type SBA-15 à base de titane, Au/titane, Ag/titane et Fe(TAML) ont tout d'abord été synthétisées et entièrement caractérisées. Des études catalytiques comparatives ont ensuite été réalisées afin d'évaluer leurs performances en termes de degré de dépolymérisation et distribution de produits. Le catalyseur présentant le plus fort potentiel, le matériau TiO2 supporté sur SBA-15, a ensuite été soumis à des études de réactivité plus poussées afin d'optimiser les différents paramètres réactionnels (température, temps de réaction et quantité d'oxydant) permettant d'atteindre en présence d'un excès d'oxydant jusqu'à 90 %pds de conversion de la lignine et à 80°C un rendement en bio-huile de 50%pds constituée principalement d'acides carboxyliques et molécules aromatiques potentiellement valorisables
Synthesis and characterization of innovative catalysts for the selective oxidation of 5-hydroxymethylfurfural by Danilo Bonincontro( )

1 edition published in 2019 in English and held by 1 WorldCat member library worldwide

L'épuisement progressif des matières premières d'origine fossile et la nécessité de réduire les émissions de gaz à effets de serre ont conduit la communauté scientifique à rechercher de nouveaux matériaux dont la production ne dépendra pas de ressources non renouvelables. Dans un autre temps ces matériaux pourront déjà être introduits sur le marché afin de substituer des produits déjà existant qui proviennent de matières premières fossiles. Par exemple, l'acide 2,5-furandicarboxylique (FDCA) obtenu par valorisation de la biomasse lignocellulosique est un potentiel substituant de l'acide téréphtalique actuellement utilisé pour la production de polyesters. En effet, le FDCA peut être obtenu par oxydation sélective du 5-hydroxyméthylfurfural (HMF) synthétisé à partir de la biomasse lignocellulosique. Ainsi, ce travail de thèse peut être défini par deux problématiques principales : (1) Le développement de catalyseurs pour l'oxydation de HMF en FDCA sans utiliser de bases inorganiques et (2) Développement de membranes catalytiques de polymères pour la future adaptation du procédé d'oxydation en réacteur à flux continu. Pour ce qui concerne l'oxydation de HMF dans des conditions neutres, une première étude s'est intéressée à la possibilité d'utiliser de l'oxyde de nickel nanométrique comme support pour des nanoparticules. Ensuite, la possibilité d'utiliser des nanoparticules de Pt supportées sur du TiO2 obtenues par décomposition contrôlée de clusters carbonyliques a été étudiée. Ainsi, des membranes de polymère obtenues par électrospinning, contenant les nanoparticules métalliques étudiées précédemment, ont été appliquées comme système catalytique pour l'oxydation du HMF
Oxydes de titane mésoporeux : synthèse, caractérisation et modification de surface by Ugo Lafont( Book )

in French and held by 1 WorldCat member library worldwide

Maîtrise de la morphologie et des propriétés de surface de silice mésoporeuse ordonnée by Thierry Martin( Book )

in French and held by 1 WorldCat member library worldwide

Additifs promoteurs d'octane à base d'offrétite pour le craquage catalytique by Marie-Thérèse Ferreira Grandmougin( Book )

in French and held by 1 WorldCat member library worldwide

Catalyseurs pour la synthèse du butadiène via le procédé Ostromyslensky développés par Chimie organométallique de surface by Pooja Gaval( )

1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

In the recent years on-purpose synthesis of butadiene using bioethanol has gained unprecedented attention owing to rise in interest for bio-based feedstock along with the steeply increasing demand for butadiene (BD). In this regard a relevant process is the Ostromyslensky's two-step process, involving dehydrogenation of ethanol to acetaldehyde in a separate step, followed by butadiene production in the second stage by co-feeding ethanol and acetaldehyde. Although the economic viability and feasibility of this ethanol to butadiene (ETB) process is well established, there is a room for better catalytic performances and selectivity. In this endeavour our aim was to develop a family of well-defined Ta-based silica-supported catalysts through Surface Organometallic Chemistry (SOMC) and test them in the conversion of EtOH/AA to BD. The first set of pre-catalysts was synthesized by treating the previously known [(=SiO)2TaHx] with N2O as mild oxidant. The second family of catalysts was prepared by calcination of the tantalum alkyl species at 500°C. The pre-catalysts were characterized by FTIR, SS NMR, UV-vis-DRS, XRD, EXAFS and HR-STEM. The N2O oxidized SOMC pre-catalysts were found to have mostly isolated [(=SiO)2Ta(OH)x] species populating the surface whereas the family of pre-catalysts synthesized via calcination evidenced a mixture of surface species, including string-like aggregations.Catalytic tests over these catalysts generated promising results exhibiting superior catalysis in the transformation of EtOH/AA to BD in terms of both BD selectivity and yield compared to the state of the art. In addition to the excellent selectivity a narrow range of product distribution and negligible coke formation was observed. Isolated TaOx species on the N2O oxidized pre-catalyst showed markedly better activity and were found to be the active sites in this conversion compared to the string-like aggregation of tantalum centres on the calcined material. Based on this and in-situ DRIFT studies over the catalysts a preliminary mechanism for this conversion was proposed
 
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Audience level: 0.94 (from 0.93 for Zeolite na ... to 0.95 for Synthesis ...)

Alternative Names
Francesco Di Renzo wetenschapper

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